1. Field of the Invention
The present invention is directed to an arrangement including a compressor gasket and head for use in an automotive air conditioning compressor.
2. Discussion of the Related Art
Air conditioning compressors may comprise a cast cylinder housing in which are formed axial cylinders that receive multiple axially movable pistons operated by a swashplate. The swashplate in turn is belt driven by the vehicle engine.
Such swashplate compressors normally comprise end plates located on either axial end of the cylinders, which are formed in the housing arranged in multiple parts. The housing parts and the end plates are bolted together in an end-to-end relationship. The end plates form valve cavities and valve elements control flow of refrigerant fluid or gas to each of the cylinders as the pistons for the respective cylinders are stroked during an intake stroke portion of the refrigeration cycle. Other valve elements are used to control the flow of fluid or gas from the end of each of the cylinders during the compressor stroke of each piston for the respective cylinders.
The manufacture and assembly of end plates and valve structure present complex machining and assembly problems, and the space occupied by the end plates and the associated valve parts creates packaging problems for air conditioning compressors in vehicle engine compartments.
U.S. Pat. No. 4,820,133 discloses a compressor design which provides a built-in cylinder housing head that forms an integral part of the compressor housing and provides inlet flow passages and high pressure discharge passages for the refrigerant that are cast in the housing head. The cylinder bodies are separate from and are enclosed within the housings and are arranged in juxtaposed relationship with respect to the ends of the housing heads in which the cast passages are formed. There is also a subassembly of intake and exhaust valve elements adjacent to each housing head. This subassembly includes a valve plate adjacent to the end of the cylinder block, a discharge valve disc defining reed valves that establish a controlled flow exit path for the high pressure fluid from the cylinders and an intake valve disc having reed valves that establish a controlled flow intake of refrigerant fluid to the cylinders. The valve plate and valve discs are purported to provide axial flow of fluid, both high pressure fluid and low pressure fluid, from one end of the cylinders to the other without the necessity for using external passage structure. These ports communicate with the axial passages formed in the cylinder blocks themselves.
The U.S. Pat. No. 133 discloses that the housing head includes a backup or stop for limiting the deflection of the discharge reed valves. There is also disclosed a sealed gasket or disc which is located between the discharge valve disc and the housing head which seals the high pressure regions of the compressor from the low pressure regions and also secures the discharge valve disc firmly against the valve plate at a radially inward location so that the base or radially inward locations of the discharge reed valves are not unduly stressed during operation.
However, it has been found that having the discharge reed valve directly contact the backup or stop of the housing head creates undesirable noise characteristics from the compressor. Thus, it is desirable to produce a compressor where this noise is reduced.